[Nagiosplug-help] check_nrpe shell command evaluation (aka backtick expressions) within nrpe command definition possible?

[Ralph.Grothe at itdz-berlin.de]

Hi,

Because miraculously various Oracle dump directories disappeared on a host
our DBA asked me to monitor their presence by Nagios.

Because I was too lazy to tinker up an own plugin 
(though this would have been most trivial for this particular task I suppose)
I first searched on Nagios Exchange for things like "check_file"
and came across a suite of Nagios plugins based on the CPAN module Nagios::Plugin
and distributed by OpenFusion.
Among them I found a check_file which I could abuse for my trivial task.

The plugin works fine, so this is not related to this check_file implementation
but rather a basic nrpe puzzle for me.

I want to exploit the shell's globbing feature
because I have no idea how many more files the DBAs might come up with
for this kind of ridiculous checks.

So I can run the check in an interactive shell like so:

$ /usr/lib/nagios/plugins/check_file -s 1 -f $(echo /home/oracle/app/oracle/admin/VIS*/[cu]dump|sed 's/ / -f /g')
FILE OK -   OK: /home/oracle/app/oracle/admin/VISABH/cdump (size 4096b), /home/oracle/app/oracle/admin/VISABH/udump (size 4096b), /home/oracle/app/oracle/admin/VISASDB/cdump (size 4096b), /home/oracle/app/oracle/admin/VISASDB/udump (size 4096b), /home/oracle/app/oracle/admin/VISJUS/cdump (size 4096b), /home/oracle/app/oracle/admin/VISJUS/udump (size 4096b), /home/oracle/app/oracle/admin/VISKVA/cdump (size 4096b), /home/oracle/app/oracle/admin/VISKVA/udump (size 4096b)

Thus I defined the following nrpe command:

$ grep dump-dirs /etc/nagios/nrpe.cfg
command[check_exist_cu-dump-dirs_VISDBS]=/usr/lib/nagios/plugins/check_file -s 1 -f $(echo /home/oracle/app/oracle/admin/VIS*/[cu]dump|sed 's/ / -f /g')


But when I execute this via check_nrpe I see that unfortunately nrpe doesn't
seem to have a notion of shell globs or command expansion.


$/usr/lib64/nagios/plugins/check_nrpe -n -H localhost -c check_exist_cu-dump-dirs_VISDBS
FILE CRITICAL - /home/oracle/app/oracle/admin/VIS*/[cu]dump$: does not exist


On the other hand, 
if I place a fully expanded command in nrpe.cfg it also fails.
I assume there's a number of characters limit such an nrpe command string may hold?

$ grep dump-dirs /etc/nagios/nrpe.cfg |tail -1
command[check_exist_cu-dump-dirs_VISDBS]=/usr/lib/nagios/plugins/check_file -s 1 -f /home/oracle/app/oracle/admin/VISABH/cdump -f /home/oracle/app/oracle/admin/VISABH/udump -f /home/oracle/app/oracle/admin/VISASDB/cdump -f /home/oracle/app/oracle/admin/VISASDB/udump -f /home/oracle/app/oracle/admin/VISJUS/cdump -f /home/oracle/app/oracle/admin/VISJUS/udump -f /home/oracle/app/oracle/admin/VISKVA/cdump -f /home/oracle/app/oracle/admin/VISKVA/udump

$ /usr/lib64/nagios/plugins/check_nrpe -n -H localhost -c check_exist_cu-dump-dirs_VISDBS
FILE CRITICAL - /home/oracle/app/oracle/admin/VISABH/cdump: does not exist :: /home/oracle/app/oracle/admin/VISABH/udump: does not exist :: /home/oracle/app/oracle/admin/VISASDB/cdump: does not exist :: /home/oracle/app/oracle/admin/VISASDB/udump: does not exist :: /home/oracle/app/oracle/admin/VISJUS/cdump: does not exist :: /home/oracle/app/oracle/admin/VISJUS/udump: does not exist :: /home/oracle/app/oracle/admin/VISKVA/cdump: does not exist :: /home/oracle/app/oracle/admin/VISKVA/udump: does not exist

But this is not true because the dirs all exist,
as can be shown

$ /usr/lib64/nagios/plugins/check_nrpe -n -H localhost -c check_exist_cu-dump-dirs_VISDBS|tr \: \\012|
grep dump|cut -d- -f2|xargs ls -ld
drwxr-xr-x  2 oracle oinstall 4096 Jun 13 17:19 /home/oracle/app/oracle/admin/VISABH/cdump
drwxr-xr-x  2 oracle oinstall 4096 Jul 23 17:45 /home/oracle/app/oracle/admin/VISABH/udump
drwxr-xr-x  2 oracle oinstall 4096 Jun 13 17:29 /home/oracle/app/oracle/admin/VISASDB/cdump
drwxr-xr-x  2 oracle oinstall 4096 Jul 23 17:45 /home/oracle/app/oracle/admin/VISASDB/udump
drwxr-xr-x  2 oracle oinstall 4096 Jun 13 17:29 /home/oracle/app/oracle/admin/VISJUS/cdump
drwxr-xr-x  2 oracle oinstall 4096 Jul 23 18:28 /home/oracle/app/oracle/admin/VISJUS/udump
drwxr-xr-x  2 oracle oinstall 4096 Jun 13 17:29 /home/oracle/app/oracle/admin/VISKVA/cdump
drwxr-xr-x  2 oracle oinstall 4096 Jul 23 17:45 /home/oracle/app/oracle/admin/VISKVA/udump